app/javascript/js/controllers/multiple_select_filter_controller.js
import BaseFilterController from './filter_controller'
export default class extends BaseFilterController {
static targets = ['selector']
getFilterValue() {
const filterValue = Array.from(this.selectorTarget.selectedOptions).map(({ value }) => value)
return filterValue.length === 0 ? null : filterValue
}
getFilterClass() {
const { filterClass } = this.selectorTarget.dataset
return filterClass
}
}